Can an element be a set?

Related questions

1. Are the rationals well ordered?
2. What is total order set?
3. Is Zfc consistent?
4. Is addition an axiom?
5. What does it mean for a set to be well ordered?
6. Does null set contain itself?
7. Is Zfc first order?
8. What is an ordering principle?
9. What is an ordering principle in English?
10. What is a true axiom?

Tags

1. #object
2. #objects
3. #defined
4. #collection
5. #element
6. #subset
7. #elements
8. #every
9. #called
10. #exactly
11. #equal